Calling activity patterns in an anuran assemblage: the role of seasonal trends and weather determinants

Calling activity of anuran assemblages were related to seasonal changes in weather factors such as temperature and rainfall. We evaluated the suitability of these variables as determinants of activity of an assemblage and compared them against a sinusoidal model that considered month as a “latent variable” related to seasonality. Activity patterns were assessed in a ten species assemblage of anurans in southern Uruguay. The sinusoidal function of month explained a larger proportion of the variability in activity and was more parsimonious than models that considered weather variables. At a seasonal scale, activity is determined by a circannual rhythm and/or responses to complex seasonal changes in environmental conditions. The sinusoidal model that uses parameters with clear biological interpretation is a good descriptor of seasonal trend in a community structure, and could be applied in other assemblages to test its generality.